Guinean Region Research Articles

Seroprevalence and risk factors of foot-and-mouth disease in sheep and goats in the Soudan-Sahelian and Guinean regions of Cameroon

Seroprevalence and risk factors of foot-and-mouth disease in sheep and goats in the Soudan-Sahelian and Guinean regions of Cameroon

Dual-purpose crops productivity and small-scale dairy farmers’ food security efforts toward climate variability and change in Benin

Dual-purpose cropping (sowing crops with the intention of both grazing them during vegetative growth and harvesting grain thereafter for household consumption) is certainly a promising way to address challenges face by small-scale dairy farmers in Benin due to climate variability and change. This study evaluated the impact of climate variability and change on dual-purpose crops productivity performances and nutritional values in Benin’s climatic regions. Four dual-purpose crops were studied. They are maize fodder, sorghum fodder, peanut fodder and cowpea fodder. The grain yield across various climate regions and years were assessed. Also fodders samples were analysed according to official methods of AOAC. The results showed that dual purposes crops yield were significantly affected particularly in some years in many regions of Benin by climate parameters variation. The variation of humidity had a negative effect on cereals dual-purpose crops production in Guinean region while the impacts of temperature and rainfall on dual purpose crops were higher in Sudanian region. The model for predicting the resistance of dual-purpose crops to climate variability and change revealed that The Annual Yield of Sorghum Grain was significantly influenced by humidity (P=0.0111), Rainfall (P=0.0374) and Weather station/Region (P=0.0493), as well as by the interaction between temperature and Grain Yield per Hectare (P=0.0423). The annual quantity of maize produced varied significantly with temperature (P=0.00154), humidity, Rainfall (P=0. 00792), Weather station/ Region (P=0.00362). The Annual Yield of Cowpea Grain production varied significantly with Temperature and Humidity (0.0205). Furthermore, temperature, humidity, year and Grain Yield per Hectare significantly affected the Annual Yield of Peanut Grain Produced. Nutritional values of the four studies dual-purpose crops were assessed. The energy values were 0.60 and 0.50 UFL/kg of Dry Matter respectively for sorghum-fodder and maize-fodder, the contents of digestible nitrogenous materials (MAD) were 1 and 0 g/kg of DM respectively for sorghum-fodder and maize-fodder. If the energy values were quite good for cereals fodder, the nitrogen values were very low. This study highlighted the nutritional advantage of leguminous fodders over cereal fodders.

Estimation of Aboveground Biomass in Agroforestry Systems over Three Climatic Regions in West Africa Using Sentinel-1, Sentinel-2, ALOS, and GEDI Data.

Agroforestry systems (AFS) offer viable solutions for climate change because of the aboveground biomass (AGB) that is maintained by the tree component. Therefore, spatially explicit estimation of their AGB is crucial for reporting emission reduction efforts, which can be enabled using remote sensing (RS) data and methods. However, multiple factors including the spatial distributions within the AFS, their structure, their composition, and their variable extents hinder an accurate RS-assisted estimation of the AGB across AFS. The aim of this study is to (i) evaluate the potential of spaceborne optical, SAR and LiDAR data for AGB estimations in AFS and (ii) estimate the AGB of different AFS in various climatic regions. The study was carried out in three climatic regions covering Côte d'Ivoire and Burkina Faso. Two AGB reference data sources were assessed: (i) AGB estimations derived from field measurements using allometric equations and (ii) AGB predictions from the GEDI level 4A (L4A) product. Vegetation indices and texture parameters were generated from optical (Sentinel-2) and SAR data (Sentinel-1 and ALOS-2) respectively and were used as predictors. Machine learning regression models were trained and evaluated by means of the coefficient of determination (R2) and the RMSE. It was found that the prediction error was reduced by 31.2% after the stratification based on the climatic conditions. For the AGB prediction, the combination of random forest algorithm and Sentinel-1 and -2 data returned the best score. The GEDI L4A product was applicable only in the Guineo-Congolian region, but the prediction error was approx. nine times higher than the ground truth. Moreover, the AGB level varied across AFS including cocoa (7.51 ± 0.6 Mg ha-1) and rubber (7.33 ± 0.33 Mg ha-1) in the Guineo-Congolian region, cashew (13.78 ± 0.98 Mg ha-1) and mango (12.82 ± 0.65 Mg ha-1) in the Guinean region. The AFS farms in the Sudanian region showed the highest AGB level (6.59 to 82.11 Mg ha-1). AGB in an AFS was mainly determined by the diameter (R2 = 0.45), the height (R2 = 0.13) and the tree density (R2 = 0.10). Nevertheless, RS-based estimation of AGB remain challenging because of the spectral similarities between AFS. Therefore, spatial assessment of the prediction uncertainties should complement AGB maps in AFS.

Changes in compound extremes of rainfall and temperature over West Africa using CMIP5 simulations

This study aims to characterize changes in compound extremes of rainfall and temperature over West Africa. For this purpose, data from CHIRPS observations, the ERA5 reanalysis, and twenty-four (24) climate models involved in the CMIP5 Project were analyzed. First, climate models were evaluated in terms of their capacity to simulate summer mean climatology and compound extremes during the historical period (1981–2005), and secondly, changes in compound extremes were examined under RCP8.5 emission scenario between the near future (2031–2055) and the far future (2071–2095) relative to the historical period. Despite the presence of some biases, the ensemble mean of the models well reproduces the compound extremes patterns over West Africa at the seasonal and intraseasonal timescales. The analysis over the historical period with CHIRPS/ERA5 dataset shows a strong occurrence of the dry/warm mode over the northern Sahel during the June-July-August-September period (JJAS; main rainy season) and over the Guinean region during the February-March-April-May season (FMAM; first and main rainy season). These strong occurrences are due to a weak and highly frequent precipitation recorded in these zones. The compound wet/warm mode is frequent in JJAS over the Sahel and the Sudanian zone (transition area between Sahel and Guinean regions), while in FMAM, its occurrence is maximum over the Guinean region. The study also shows that the dry/warm mode will increase in the whole Sahel (western and central) and in the Guinean zone in the near and far futures while the compound wet/warm mode will decrease in the whole region. This study suggests that the West Africa region will be prone to drought intensified by warmer temperatures and calls for climate action and adaptation strategies to mitigate the risks on rain-fed agriculture, energy, and on animals and human health.

Rice yield stability compared to major food crops in West Africa

West Africa is one of the regions the most concerned with structural food and nutrition security. Consequently, agricultural development pathways and scenarios are under high scientific and political scrutiny in this region. Rice, as a rapidly growing staple plays a key role in the West African diet representing close to 40% of the total volume of cereal consumed in the region. In the context of the 2008 food price crisis several West African countries have since proclaimed rice self-sufficiency as a target. Here, we show that rice yields tend to be, on average over the entire region, less stable (by a range of 15%–30%) than that of alternative crops, possibly substitutable in diets. The regions where yields of alternative crops are more stable than those of rice correspond to the main climatic regions where these crops are grown: sorghum, millet in the Sahelian and Sudanian regions and tubers in the Guinean region. Rice yields are significantly less stable for 33% of the comparisons considered and are significantly more stable than any alternative crop for 15% of the comparisons in few areas without clear longitudinal patterns. Models accounting for climate variability explain up to 17% of the variance of the data and reveal that yield variability differences between rice and alternative crops tends to widen in the areas where the monsoon precipitation is more variable between-years. The highest levels of variability of rice yields compared to alternative crops are recorded in regions where the monsoon varies strongly between years. Our analysis advocates for an explicit account of yield stability in West African rice expansion scenarios and supply strategies.

Daytime low-level clouds in West Africa – occurrence, associated drivers, and shortwave radiation attenuation

Abstract. This study focuses on daytime low-level clouds (LLCs) that occur within the first 2 km of the atmosphere over West Africa (WA). These daytime LLCs play a major role in the earth's radiative balance, yet their understanding is still relatively low in WA. We use the state-of-the-art ERA5 dataset to understand their occurrence and associated drivers as well as their impact on the incoming surface solar radiation in the two contrasting Guinean and Sahelian regions of WA. The diurnal cycle of the daytime occurrence of three LLC classes namely No LCC, LLC Class-1 (LLCs with lower fraction), and LLC Class-2 (LLCs with higher fraction) is first studied. The monthly evolutions of hourly and long-lasting LLC (for at least 6 consecutive hours) events are then analyzed as well as the synoptic-scale moisture flux associated with the long-lasting LLC events. Finally, the impact of LLC on the surface heat fluxes and the incoming solar irradiance is investigated. During the summer months in the Guinean region, LLC Class-1 occurrence is low, while LLC Class-2 is frequent (occurrence frequency around 75 % in August). In the Sahel, LLC Class-1 is dominant in the summer months (occurrence frequency more than 80 % from June to October); however the peak occurrence frequency of Class-2 is also in the summer. In both regions, events with No LLC do not present any specific correlation with the time of the day. However, a diurnal evolution that appears to be strongly different from one region to the other is noted for the occurrence of LLC Class-2. LLC occurrence in both regions is associated with high moisture flux driven by strong southwesterly winds from the Gulf of Guinea and significant background moisture levels. LLC Class-2 in particular leads to a significant reduction in the upward transfer of energy and a net downward energy transfer caused by the release of large amounts of energy in the atmosphere during the cloud formation. In July, August, and September (JAS), most of the LLC Class-2 events may likely be the low-level stratiform clouds that occur frequently over the Guinean region, while they may be deep convective clouds in the Sahel. Additionally, LLC Class-2 causes high attenuation of the incoming solar radiation, especially during JAS, where about 49 % and 44 % of the downwelling surface shortwave radiation is lost on average in Guinea and the Sahel, respectively.

Characterizing vegetation response to rainfall at multiple temporal scales in the Sahel-Sudano-Guinean region using transfer function analysis

Rainfall is a key driver of terrestrial vegetation. Clarifying the response mechanism of vegetation to rainfall can advance the understanding of expected changes in ecosystems under projected rainfall scenarios. Besides the rainfall amount over a period of time, the frequency, duration and intensity are of importance in driving ecosystem processes. The pulsating nature of rainfall forcing and of vegetation response applies particularly to arid and semi – arid regions and led to conceptualize the “pulse-reserve” paradigm, which we used to explain the approach we propose in this study. We introduce the Transfer Function Analysis (TFA) method in the frequency domain to capture the response of vegetation to rainfall at multiple temporal scales. The TFA method determines coherence, gain, and phase to characterize the existence, strength, and time-lag, respectively, of the vegetation response to rainfall at different temporal scales. Specifically, the coherence measures the existence of the response and only with a significant response are the gain and phase values significant and valuable for further analysis. The gain measures the strength of the relationship between fluctuations in vegetation growth and fluctuations in rainfall, while the phase value (i.e. the time-lag) measures how fluctuations in vegetation growth lag (or lead) fluctuations in rainfall. The TFA method was applied to the 34-years (1982–2015) NDVI3g and CHIRPS precipitation dataset in the Sahel-Sudano-Guinean region (20°W ~ 60°E, 0–25°E). The Sahelian zone was characterized by a significant vegetation response to rainfall across all inter- and intra- annual time-scales, while the Sudano-Guinean zone was dominated by significant response at annual or 6-month scales. The negative phase lag indicated that rainfall variation normally led NDVI change for most areas and across timescales. However, a positive phase observed in part of the tropical rainforest area indicated that NDVI changes led rainfall variations, which may be caused by the strong vegetation-rainfall feedback through recycling of precipitation by evapotranspiration. In summary, these results suggested that the TFA method is a powerful tool to quantify the vegetation-rainfall response regime across a range of timescales, as conceptualized by the “pulse-reserve” paradigm. Unraveling the response of fluctuations in vegetation growth to separate components of the forcing by precipitation might improve our understanding of environmental change in the past decades in the Sahel - Sudan - Guinean region.

Antimicrobial investigation of ethnobotanically selected guinean plant species

Ethnopharmacological relevanceIn Guinea, medicinal plants play an important role in the management of infectious diseases including urinary disorders, skin diseases and oral diseases. This study was carried out to collect medicinal plant species employed for the treatment of these diseases and to investigate their antimicrobial potential. Materials and methodsBased on an ethnobotanical investigation carried out in three Guinean regions, 74 traditional healers and 28 herbalists were interviewed and medicinal plants were collected. The most quoted plant species were evaluated for their antimicrobial activities against Staphylococcus aureus, Escherichia coli, Candida albicans, and in addition against Plasmodium falciparum. ResultsA total of 112 plant species belonging to 102 genera distributed over 42 botanical families were inventoried. Among the selected plant species, promising activities against C. albicans were obtained for the methanolic extracts of the stem bark of Terminalia albida (IC50 1.2 μg/ml), the leaves of Tetracera alnifolia (IC50 1.6 μg/ml) and the root bark of Swartzia madagascariensis (IC50 7.8 μg/ml). The highest activity against S. aureus was obtained for the dichloromethane extracts of the leaves of Pavetta crassipes (IC50 8.5 μg/ml) and the root of Swartzia madagascariensis (IC50 12.8 μg/ml). Twenty one extracts, obtained from twelve plant species, were strongly active against Plasmodium falciparum, including the dichloromethane extracts of the root and stem bark of Terminalia albida root (IC50 0.6 and 0.8 μg/ml), the leaves of Landolphia heudelotii (IC50 0.5 μg/ml), the stem bark of Combretum paniculatum (IC50 0.4 μg/ml) and the leaves of Gardenia ternifolia (IC50 1.3 μg/ml). ConclusionThe present study provides a comprehensive overview of medicinal plants employed by Guinean traditional healers for the treatment of various microbial diseases, including urinary disorders, skin diseases and oral diseases. Some of the studied plant species showed promising antimicrobial activity and could be considered as a potential source for the development of new antifungal and/or antimalarial agents.

Uncertainties in the Annual Cycle of Rainfall Characteristics over West Africa in CMIP5 Models

We analyse uncertainties associated with the main features of the annual cycle of West African rainfall (amplitude, timing, duration) in 15 CMIP5 simulations over the Sahelian and Guinean regions with satellite daily precipitation estimates. The annual cycle of indices based on daily rainfall such as the frequency and the intensity of wet days, the consecutive dry (CDD) and wet (CWD) days, the 95th percentile of daily rainfall (R95), have been assessed. Over both regions, satellite datasets provide more consistent results on the annual cycle of monthly precipitation than on higher-frequency rainfall indices, especially over the Guinean region. By contrast, CMIP5 simulations display much higher uncertainties in both the mean precipitation climatology and higher-frequency indices. Over both regions, most of them overestimate the frequency of wet days. Over the Guinean region, the difficulty of models to represent the bimodality of the annual cycle of precipitation involves systematic biases in the frequency of wet days. Likewise, we found strong uncertainties in the simulation of the CWD and the CDD over both areas. Finally, models generally provide too early (late) onset dates over the Sahel (the Guinean region) and overestimate rainfall during the early and late monsoon phases. These errors are strongly coupled with errors in the latitudinal position of the ITCZ and do not compensate at the annual scale or when considering West Africa as a whole.

Effect of the African greenbelt position on West African summer climate: a regional climate modeling study

This modeling study is conducted to examine the potential impact of the reforestation (greenbelt) location (either in Sahel or in Guinean region) on West African summer climate system. To this end, three simulations using the regional climate model RegCM4 driven by ERA-Interim reanalysis were performed at 50 km horizontal resolution over a West African domain for the period 2000–2011. The first experiment, namely the control (CTRL), uses the standard vegetation cover, while the two others incorporate throughout the model integration, a zonal reforestation band of evergreen broadleaf over different locations: (i) over a 13° N–17° N band latitudes in a Sahel-Sahara region (experiment hereafter referred to as GB15N) and (ii) between 8.5° N–11.5° N in the Guinea Coast region (experiment hereafter referred to as GB10N). A comparison of the CTRL experiment with observation reveals a faithful reproduction of the mean boreal and summer seasonal precipitation pattern, though substantial dry/wet biases remain, especially in the Atlantic Ocean. In addition, the seasonal cycle over sub-regions matches satisfactory the observed pattern. The GB15N reforestation leads to a precipitation increase in the range of 2–4 mm/day over the forested areas, whereas in the GB10N reforestation, precipitation increase is weaker and not necessarily located in the forested areas. Temperature cooling is observed over the reforested area and may be explained by a decrease of ground heat flux related to a reduction of the surface albedo.

Biodiversity of indigenous Djallonke sheep (Ovis aries) in Sudano Guinean region in Cameroon

In order to study the biodiversity of Cameroon indigenous Djallonke sheep, a study was conducted between July and September 2016 in the Sudano-Guinean zone of Cameroon. A total of 280 adult sheep (24 months old) including 77 males and 203 females from 112 farms in 13 districts of 4 divisions was measured and analyzed. The variance analysis showed variability in the population. According to the principal components analysis, the body length, chest circumference, withers height and the live weight were potentially discriminating characters of the ovine population studied. The discriminant analysis revealed a population made of three genetic types with genetic type I having the highest characteristics. The phylogenetic analysis showed that type II and III are closer and type I and III are genetically more distant. High intra-genetic variability was observed within the population studied. The linearregression equation (LW = 0.8092CG + 58.923) with a coefficient of determination (R2 = 0.66) predicts better the live weight. This results offer possibilities for genetic improvement. Characterization, leading to conservation and sustainable use of indigenous sheep genetic resources in Cameroon’s smallholder production system. The possible threats to the current potentials may be genetic erosion, climate change, low productivity and disease susceptibility.

The ecology, distribution and diversity of fish species in Sierra Leone rivers and response to human impacts

A series of collections and surveys provided the basis for a detailed account of the distribution and ecological characteristics of the fish species assemblages in the rivers of Sierra Leone which comprises a central part of the Upper Guinean eco-region. Within and between river differences were analysed and a high degree of statistical similarity was found between the species composition of the major rivers. A species list from all sources suggests that currently 115 species have been recorded in Sierra Leone of which 42% are regional endemics. Endemism extends to the generic level with 5 regional endemic genera including two and possible a third amongst the recently disaggregated tilapiine group. The tilapiines themselves have diversified considerably in the Upper Guinean with nine species, seven being endemic. The drivers of this considerable diversification generally in the Upper Guinean are discussed. Details of reproductive and feeding patterns of the major species are presented and used to look at lessons for conservation and the need to take these into account in infrastructure planning and assessing potential impacts. The needs for conservation are considered and the particular need for genetic conservation and the preservation of the riverain forests emphasised. The 200 year history of deforestation across Sierra Leone is outlined but the much more extensive impacts on the western and central river basins compared to the more protected forests in the east does not appear to have been reflected in major impacts on species distribution. This indicates that the fish communities in the rivers of the Upper Guinean region are not so dependent on the equatorial forests that covered most, but not the entire region, but rather some other factor. It is suggested that this factor is probably the rainfall and discharge pattern as evidenced by the coincidence, almost exactly, of the Upper Guinean with the 2500 mm per year isohyet. Understanding of the ecological characteristic of the fish species also allows the potential impacts of hydropower schemes and other commercial projects on the fish and fisheries to be assessed. Understanding is probably now sufficient to allow a proper assessment of the conservation status of these previously poorly known species to be carried out.

Fire Regimes and Their Drivers in the Upper Guinean Region of West Africa

The Upper Guinean region of West Africa exhibits strong geographic variation in land use, climate, vegetation, and human population and has experienced phenomenal biophysical and socio-economic changes in recent decades. All of these factors influence spatial heterogeneity and temporal trends in fires, but their combined effects on fire regimes are not well understood. The main objectives of this study were to characterize the spatial patterns and interrelationships of multiple fire regime components, identify recent trends in fire activity, and explore the relative influences of climate, topography, vegetation type, and human activity on fire regimes. Fire regime components, including active fire density, burned area, fire season length, and fire radiative power, were characterized using MODIS fire products from 2003 to 2015. Both active fire and burned area were most strongly associated with vegetation type, whereas fire season length was most strongly influenced by climate and topography variables, and fire radiative power was most strongly influenced by climate. These associations resulted in a gradient of increasing fire activity from forested coastal regions to the savanna-dominated interior, as well as large variations in burned area and fire season length within the savanna regions and high fire radiative power in the westernmost coastal regions. There were increasing trends in active fire detections in parts of the Western Guinean Lowland Forests ecoregion and decreasing trends in both active fire detections and burned area in savanna-dominated ecoregions. These results portend that ongoing regional landscape and socio-economic changes along with climate change will lead to further changes in the fire regimes in West Africa. Efforts to project future fire regimes and develop regional strategies for adaptation will need to encompass multiple components of the fire regime and consider multiple drivers, including land use as well as climate.

Climate-induced morphological variation of black plum (Vitex doniana Sw.) in Benin, West Africa

There are evidences that plant morphology is shaped by genotype, but local environment mainly climate influences morphology as well. In this study the morphological variability of Vitex doniana, a multipurpose tree species was characterised in relation with climatic parameters in order to provide insights to the species possible responses to future climate change. Morphological data were collected on 102 trees randomly selected along unfixed transects in the three climatic zones of Benin. Data were collected on fruiting trees at three levels: tree (trunk and canopy), leaves and fruits. Variance components were estimated for identification of variability sources regarding leaves and fruits characteristics. The most important discriminant descriptors regarding climatic zones were selected through a stepwise discriminant analysis. Relationship between those discriminant morphological traits and bioclimatic variables were assessed through a redundancy analysis. Our findings confirmed that there is an important variability of morphological traits of the species and climate, mainly some of its extremes parameters plays a non-negligible role. Trees in the Sudanian region are the biggest with fruits producing little pulp while individuals in the more humid Guinean region present a higher amount of pulp whereas Sudano-Guinean trees are the tallest with larger leaves. Although the climate-induced variability of the species is relatively low, the study gives insights in probable effects of climate variability on its morphology. Population genetic studies are required for a better understanding of climatic impacts on V. doniana in order to develop selection and domestication schemes which could contribute to its conservation.

Ethnomedical and ethnobotanical investigations on the response capacities of Guinean traditional health practioners in the management of outbreaks of infectious diseases: The case of the Ebola virus epidemic

Ethnopharmacological relevanceThe recent outbreak of Ebola virus infections has mostly remained confined to the West African countries Guinea-Conakry, Sierra-Leone and Liberia. Due to intense national and international mobilizations, a significant reduction in Ebola virus transmission has been recorded. While international efforts focus on new vaccines, medicines and diagnostics, no coherent national or international approach exists to integrate the potential of the traditional health practitioners (THPs) in the management of infectious diseases epidemics. Nevertheless, the first contact of most of the Ebola infected patients is with the THPs since the symptoms are similar to those of common traditionally treated diseases or symptoms such as malaria, hemorrhagic syndrome, typhoid or other gastrointestinal diseases, fever and vomiting. Materials and methodsIn an ethnomedical survey conducted in the 4 main Guinean regions contacts were established with a total of 113 THPs. The socio-demographic characteristics, the professional status and the traditional perception of Ebola Virus Disease (EVD) were recorded. ResultsThe traditional treatment of the main symptoms was based on 47 vegetal recipes which were focused on the treatment of diarrhea (22 recipes), fever (22 recipes), vomiting (2 recipes), external antiseptic (2 recipes), hemorrhagic syndrome (2 recipes), convulsion and dysentery (one recipe each). An ethnobotanical survey led to the collection of 54 plant species from which 44 identified belonging to 26 families. The most represented families were Euphorbiaceae, Caesalpiniaceae and Rubiaceae. Literature data on the twelve most cited plant species tends to corroborate their traditional use and to highlight their pharmacological potential. ConclusionsIt is worth to document all available knowledge on the traditional management of EVD-like symptoms in order to evaluate systematically the anti-Ebola potential of Guinean plant species.

A revised checklist of Cape Verde Islands sea fishes

Summary During ichthyological research and teaching activities in the Cape Verde Archipelago, the authors noticed that the readily available inventories of its sea fishes underrepresented the mesopelagic species, contrary to an older Spanish list, which regrettably remained widely unknown. These inventories were compared, revised, combined and commented on, plus a multitude of individual descriptions, survey reports, biogeographical treatises, and unpublished data were put in a checklist. From the resulting list of 1046 names thus far reported, 779 species are supported by records, respectively, their general zoogeography. Another 29 records need confirmation. Seventeen (in the literature, up to 20) species are believed to be endemic. The list comprises 91 first records, plus many earlier records from previously disregarded literature. Seventy-five other names are erroneous either by synonym, misidentification, or misspelling. In 64 cases earlier listings referred to an erroneous geographical location. The number of recorded species will likely increase with future ichthyological research. The ichthyofauna of the Cape Verde Islands is composed mainly of widely distributed species, plus those from the Guinean Region, a few endemics, several amphi-Atlantic species, as well as shore fishes from the NW African coast.

Phylogenetic species identification in Rattus highlights rapid radiation and morphological similarity of New Guinean species.

The genus Rattus is highly speciose, the taxonomy is complex, and individuals are often difficult to identify to the species level. Previous studies have demonstrated the usefulness of phylogenetic approaches to identification in Rattus but some species, especially among the endemics of the New Guinean region, showed poor resolution. Possible reasons for this are simple misidentification, incomplete gene lineage sorting, hybridization, and phylogenetically distinct lineages that are unrecognised taxonomically. To assess these explanations we analysed 217 samples, representing nominally 25 Rattus species, collected in New Guinea, Asia, Australia and the Pacific. To reduce misidentification problems we sequenced museum specimens from earlier morphological studies and recently collected tissues from samples with associated voucher specimens. We also reassessed vouchers from previously sequenced specimens. We inferred combined and separate phylogenies from two mitochondrial DNA regions comprising 550 base pair D-loop sequences and both long (655 base pair) and short (150 base pair) cytochrome oxidase I sequences. Our phylogenetic species identification for 17 species was consistent with morphological designations and current taxonomy thus reinforcing the usefulness of this approach. We reduced misidentifications and consequently the number of polyphyletic species in our phylogenies but the New Guinean Rattus clades still exhibited considerable complexity. Only three of our eight New Guinean species were monophyletic. We found good evidence for either incomplete mitochondrial lineage sorting or hybridization between species within two pairs, R. leucopus/R. cf. verecundus and R. steini/R. praetor. Additionally, our results showed that R. praetor, R. niobe and R. verecundus each likely encompass more than one species. Our study clearly points to the need for a revised taxonomy of the rats of New Guinea, based on broader sampling and informed by both morphology and phylogenetics. The remaining taxonomic complexity highlights the recent and rapid radiation of Rattus in the Australo-Papuan region.

Pholcid spiders from the Lower Guinean region of Central Africa: an overview, with descriptions of seven new species (Araneae, Pholcidae)

This paper summarizes current knowledge about Central African pholcids. Central Africa is here defined as the area between 10°N and 7°S and between 6°E and 18°E, including mainly the Lower Guinean subregion of the Guineo-Congolian center of endemism. This includes all of Gabon, Equatorial Guinea, São Tomé and Príncipe, most of Cameroon and Congo Republic, and parts of the neighboring countries. An annotated list of the 14 genera and 79 species recorded from this area is given, together with distribution maps and an identification key to genera. Seven species are newly described: Anansus kamwai sp. nov., Leptopholcus gabonicus sp. nov., Ninetis faro sp. nov., Pholcus punu sp. nov., P. rawiriae sp. nov., Spermophora abibae sp. nov., and S. awalai sp. nov. Additional new records are given for 16 previously described species, including 17 new country records. Distribution and diversity patterns are compared with data on West and East Africa. While West Africa contains a similar set of genera it is significantly less diverse than Central Africa. East Africa is taxonomically more distinct. It has similar levels of diversity as Central Africa, but appears to be less undersampled.

Differences between cropland and rangeland MODIS phenology (start-of-season) in Mali

Start-of-season data are more and more used to qualify the land surface phenology trends in relation with climate variability and, more rarely, with human land management. In this paper, we compared the phenology of rangeland vs cropped land in the Sahel belt of Africa, using the only currently available global phenology product (MODIS MCD12Q2 – Land Cover Dynamics Yearly), and an enhanced crop mask of Mali. The differences in terms of start-of-season (SOS) are spatially (north south gradient), and temporally (10 years, 2001–2009) analyzed in bioclimatic terms. Our results show that globally the MODIS MCD12Q2 SOS dates of croplands and rangelands differ, and that these differences depend on the bioclimatic zone. In Sahelian and Guinean regions, cropland vegetation begins to grow earlier than rangeland vegetation (8-day and 4-day advance, respectively). Between, in the Sudanian and Sudano-Sahelian parts of Mali, rangeland vegetation greens about one week earlier than croplands. These results are discussed in the context of the land surface heterogeneity at MODIS scale, and in the context of the natural vegetation ecology. These results could help interpreting phenological trends in climate change analysis.

Comparative phylogeography of African rain forest trees: A review of genetic signatures of vegetation history in the Guineo-Congolian region

The biogeographic history of the African rain forests has been contentious. Phylogeography, the study of the geographic distribution of genetic lineages within species, can highlight the signatures of historical events affecting the demography and distribution of species (i.e. population fragmentation or size changes, range expansion/contraction) and, thereby, the ecosystems they belong to. The accumulation of recent data for African rain forests now enables a first biogeographic synthesis for the region. In this review, we explain which phylogeographic patterns are expected under different scenarios of past demographic change, and we give an overview of the patterns detected in African rain forest trees to discuss whether they support alternative hypotheses regarding the history of the African rain forest cover. The major genetic discontinuities in the region support the role of refugia during climatic oscillations, though not necessarily following the classically proposed scenarios. We identify in particular a genetic split between the North and the South of the Lower Guinean region. Finally we provide some perspectives for future study.